Wood Group Kenny (WGK) has announced that findings from the first and second phases of a Joint Industry Project into understanding the effect of slug flow on pipelines and risers has led to significant enhancements in their software package, Flexcom, to deliver automated slug capabilities.
Subsea systems transporting liquids and gases together as multiphase flow can all be subject to slug loading and response. A common form of flow variation is slug flow, in which liquid flows intermittently along the pipes in a concentrated mass, called a slug. Slugs can cause different problems in different subsea systems and require careful consideration during the design.
Problems that have been encountered as a result of not accurately considering slug loading at the design stage include temporary shutdowns, costly intervention work, retrospective installation of monitoring equipment and modifications to operating conditions.
Historically, at design stage the issue of slugging-induced loading has not been considered in a consistent manner and the overall objective of the Slug Loading and Response in Pipelines (SLARP) JIP is to develop and validate a consistent methodology for modelling global slug loading. Through continuous interaction with the SLARP JIP, WGK’s Flexcom team developed and implemented an enhanced slug flow model in the software, the first of its kind available commercially.
The Flexcom package now enables users to specify slug head and tail velocity, density and length as a function of time. A number of other enhancements not specifically SLARP related further increase its capabilities for slugging analysis.
Phase 3 of the SLARP JIP, which kicks off later this year, will target remaining uncertainties due to variables including pipeline diameter, viscosity and continuous slug flow. WGK are preparing to make further enhancements to the slugging capabilities of the Flexcom software as a result of the findings of this final phase.